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Exam 2 Lecture Notes Flashcards

1
Q

Name the two acidemias that are defects in the propionate catabolism pathway:

A
  • propionic acidemia (PA)
  • methylmalonic acidemia (MMA)
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2
Q

PA (propionic acidemia) is caused by a deficiency of ____, a biotin dependent enzyme.

A

PPC
(propionyl-CoA)

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3
Q

MMAs (methylmalonic acidemia) are caused by deficient activity of ___________ mutase.

A

methylmalonyl-CoA mutase

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4
Q

Vitamin ___ is a cofactor for the methylmalonyl-CoA mutase.

A

B12

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5
Q

Dietary therapy is the mainstay of long-term management in PA and MMA. In addition, intermittent courses of antibiotics reduce the production of _______ from anaerobic bacterial fermentation of carbohydrates in the gut.

A

propionyl-CoA

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6
Q

What is a major precursor of glucose (gluconeogenesis) via the citric acid cycle?

A

propionyl-CoA

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7
Q

Propionic acid is a product of catabolism of met, thr, val, and ile. What is it converted to in the TCA cycle?

A

succinyl CoA

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8
Q

An infant has increased blood levels of glycine and ammonia, which may contribute to encephalopathy. What could they have?

A

propionic academia

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9
Q

What should you administer for an infant that has propionic academia?

A

carnitine and biotin

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10
Q

If a pt has methylmalonic academia, what should you restrict?

A

met, val, ile, thr

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11
Q

Maple syrup urine disease is caused by a deficiency in what enzyme?

A

a-ketoacid dehydrogenase

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12
Q

If a pt has MSUD (maple syrup urine disease), what two amino acids should you introduce to maximize the rate of reduction of plasma leucine concentration?

A

isoleucine and valine

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13
Q

What BCAAs should you limit in MSUD?

A

val, leu, ile

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14
Q

Chronic management of glutamic acuduria includes a low ____ diet and carnitine supplementation.

A

lysine

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15
Q

Arginine competes with _____ for uptake via a specific transporter at the BBB.

A

lysine

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16
Q

Hyperhomocysteinemia and homocystinuria result from a defective metabolism of _______ due to vitamin deficiencies (B6, B12, folic acid)

A

homocysteine

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17
Q

_____ is found in high concentrations in the lens and maintains protein thiols in the reduced state, which helps to maintain lens transparency by preventing formation of high molecular weight crystallin aggregates.

A

glutathione

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18
Q

In the lens, 3-hydroxykynurenineglucoside (kynerenine) is made from what amino acid?

A

tryptophan

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19
Q

In cystathionine B-synthase deficiency, accumulation of homocysteine and/or cysteine deficiency induces modification of connective tissue proteins related to _____.

A

fibrillin

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20
Q

________ reduces the amount of fibrillin-1 C-terminal multimers and dose and time dependently affects the fibrillin-1 self-interaction.

A

homocysteine

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21
Q

What is the most common ocular manifestation of homocystinuria?

A

a defect of sulfur amino acid metabolism

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22
Q

Multi carboxylase deficiency is a deficiency of what two things?

A
  • biotinidase deficiency
  • holocarboxylase synthetase deficiency
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23
Q

What clinical presentations will an infant with biotinidase deficiency or holocarboxylase synthetase deficiency display?

A
  • seizures
  • alopecia
  • ataxia
  • skin rash
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24
Q

What is the treatment for homocystinuria?

A
  • low methionine diet
  • betaine supplements (increases methionine levels)
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25
What should be avoided in a pts diet if they have multiple carboxylase deficiency?
raw eggs because they contain avidin, a protein that binds to biotin and decreases vitamin's availability we want to increase biotin in these patients!
26
If a pt has biotinidase deficiency and holocarboxylase synthetase deficiency, what will be affected in gluconeogenesis?
pyruvate carboxylase
27
If a pt has biotinidase deficiency and/or holocarboxylase synthetase deficiency, what will be affected in lipid metabolism?
- acetyl-CoA carboxylase - propionyl-CoA
28
If a pt has biotinidase deficiency and/or holocarboxylase synthetase deficiency, what will be affected in amino acid catabolism?
- 3-methylcrotonyl-CoA - propionyl-CoA
29
In pyruvate dehydrogenase complex deficiency, pyruvate can't turn into ______, which turns into ketone bodies as a result.
acetyl-CoA
30
What is made if pyruvate can't go to acetyl-CoA?
acetone (ketones!)
31
Dichloroacetate and phenyl butyrate both inhibit ______ dehydrogenase kinase activating the PDC.
pyruvate dehydrogenase kinase
32
What is blocked in people with albinism?
conversion of tyrosine to melanin is blocked due to defects in tyrosinase
33
Parkinson disease is the result of loss of conversion of ___________ to the neurotransmitter dopamine.
dihydroxyphenylalanine
34
What inhibits dopa decarboxylase to prevent uptake of dopa?
carbidopa
35
The infantile form of Parkinson disease is due to defects in _____ hydroxylase.
tyrosine
36
In Parkinson disease, the major mitochondrial defect is associated with _____ ___ (NADH dehydrogenase activity).
complex I
37
In Parkinsons, ________ forms adducts with lysosomal vacuolar type H+-ATPase, resulting in a pH increase.
aminochrome
38
In Parkinsons, _______ is neurotoxic as it induces mitichondrial dysfunction and protein aggregation.
aminochrome
39
What is an essential cofactor in the hydroxylations of the aromatic amino acids?
tetrahydrobiopterin
40
Defects in the biosynthesis or regeneration of tetrahydrobiopterin (TBH) can lead to secondary _______.
phenylketonuria (PKU)
41
In pts with PKU, phe is converted to phenylpyruvate and then to phenyllactate and to _______.
phenylacetate
42
Phenylalanine ammonia lyase is a bacteria derived enzyme that catalyzes the conversion of L-phenylalanine to _______ acid and ammonia without a cofactor requirement.
transcinnamic
43
What is an alternative enzyme that can substitute for PAH (phenylalanine hydroxylase) by reducing the phenylalanine concentration in PKU?
PAL (phenylalanine ammonia lyase)
44
Deficient _______ oxidase activity in the liver, causes excretion of large quantities of HGA daily in the urine, which turns dark on standing.
homogentisic oxidase
45
In L-Arginine:Glycine Aminotransferase Deficiency, _______ acid is low to low normal in urine and plasma and creatinine is low in plasma.
guanidinoacetic acid (GAA)
46
Cancer cells consume what amino acid?
tryptophan
47
What blocks immune responses in cancer?
kynurenine
48
Decreased cirtulline and arginine can cause hyperammonemia. An increase in ortic acid (OU) is caused by what deficiency?
OTC deficiency
49
Decreased cirtulline and arginine can cause hyperammonemia. If there's a increase in ortic acid (OU) what deficiency will you have?
NAGS, CPS1
50
Increased cirtulline and arginine can cause hyperammonemia. An increase in ASA (argininosuccinic acid) is caused by what deficiency?
ASL deficiency (argininosuccinate lyase)
51
Decreased cirtulline and arginine can cause hyperammonemia. What deficiency causes ASA to be absent?
ASS deficiency (argininosuccinate synthetase)
52
If cirtulline is normal and arginine is increased, what deficiency will you have?
ARG1 deficiency
53
What syndrome is caused by an increase in ornithine and homocitrulline in the urea cycle?
HHH syndrome
54
Fatty acid oxidation disorder (FAOD) like carnitine metabolism defects, can lead to what?
hyperammonemia
55
Organic academias and pathological organic acids can cause what?
hyperammonemia
56
A new born has hypoglycemia with ketosis and a normal lactate. What's your differential diagnosis?
organic acidemia adrenal insufficiency
57
A new born has hypoglycemia with ketosis and a high lactate. What's your differential diagnosis?
- FBPase deficiency (fructose-1, 6-biphosphatase) - GSD1 (glycogen storage disease type 1) - Respiratory chain defects
58
A new born has hypoglycemia without ketosis and a normal lactate. What's your differential diagnosis?
hyperinsulinism (inc insulin, dec glucose)
59
A new born has hypoglycemia without ketosis and a high lactate. What's your differential diagnosis?
- FAO defect (fatty acid oxidation) - HMG CoA lyase deficiency (3-hydroxy-3-methylglutaryl coenzyme A)
60
Do saturated lipids decrease or increase fluidity?
decrease
61
Do unsaturated lipids increase or decrease fluidity?
increase
62
Does cholesterol increase or decrease membrane fluidity?
decrease
63
Spur cell anemia, a type of hemolytic anemia, is characterized by levels of ______ in erythrocyte membrane, which decrease the fluidity and flexibility of the membranes.
cholesterol
64
Pts with a defective amino acid transporter that leads to cystinuria present with what?
renal colic (abdominal pain linked to kidney stones)
65
_______ is an autosomal recessive disease caused by a defect in the transport system responsible for the uptake of the dimeric amino acid cystinex, and dibasic amino acids arg, lys, and ornithine.
cystinuria
66
______ disease is an autosomal recessive disorder caused by a defect in a transporter for non polar or neutral main acids.
hartnup disease
67
What disease manifests in infancy as failure to thrive, nystagmus, intermittent ataxia, tremor, and photosensitivity?
hartnup disease
68
Loss of function mutations in human _______ have been found to cause severe epilepsy that could be due to dysfunction of GABA signaling and hyperfunction of NMDA receptor signaling.
human SLC13A5
69
Intracellular citrate levels decrease while extracellular citrate levels increase when _____ function is lost.
SLC13A5
70
Increased homocysteine and increased methionine is caused by a deficiency of what?
cystathionine B-synthase deficiency
71
Increased homocysteine and decreased methionine is caused what 3 deficiencies?
- methylenetetrahydrofolate reductase deficiency - methyltransferase reductase - methionine synthase deficiency
72
Increased homocysteine and with a slight decrease methionine and slight increase in methylmalonic acid is caused by a deficiency of what?
cobalamin deficiency
73
The disorder of argininemia is caused by what enzymatic defect?
arginase
74
The disorder of argininosiccinic aciduria is caused by what enzymatic defect?
arginosuccinate lyase
75
The disorder of citrullinemia is caused by what enzymatic defect?
arginiosuccinate synthetase
76
The disorder of homocystinuriais caused by what enzymatic defect?
cystathionine B-synthase
77
The disorder of make syrup urine disease is caused by what enzymatic defect?
branched chain a-keto acid dehydrogenase complex
78
The disorder of ornithine transcarbamylase deficiency is caused by what enzymatic defect?
ornithine transcarbamylase
79
The disorder of phenylketonuria is caused by what enzymatic defect?
phenylalanine hydroxylase
80
The disorder of tyrosinemia type 1 is caused by what enzymatic defect?
fumaryl acetoacetase
81
The disorder of tyrosinemia type 2 is caused by what enzymatic defect?
tyrosine aminotransferase
82
The disorder of glutamic acuduria type 1 is caused by what enzymatic defect?
glutaryl-CoA dehydrogenase
83
The disorder of holocarboxylase synthetase deficiency is caused by what enzymatic defect?
holocarboylase synthetase
84
The disorder of isobutyric aciduria is caused by what enzymatic defect?
isobutyryl-CoA dehydrogenase
85
The disorder of isovaleric aciduria is caused by what enzymatic defect?
isovaleryl-Coa dehydrogenase
86
The disorder of methylmalonic aciduria is caused by what enzymatic defect?
methylmalonyl-CoA dehydrogenase
87
The disorder of mevalonic aciduria is caused by what enzymatic defect?
mevalonate kinase
88
The disorder of propionic aciduria is caused by what enzymatic defect?
propionyl-CoA carboxylase

Biochem (4 decks)

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